Booster seat



FIG. 1 is a front elevational view of a booster seat, showing my new design, the broken lines are for environmental purposes only and form no part of the claimed design;

FIG. 2 is a top plan view of the booster seat;

FIG. 3 is a side elevational view of the booster seat, the reverse side being the same;

FIG. 4 is a bottom plan view of the booster seat; and,

FIG. 5 is an end elevational view of the booster seat, the reverse side being the same. 

The ornamental design for a booster seat, as shown and described. 